[0353/1094] drm/i915: Don't use HDMI 12bpc when cloning with other encoder types

Commit Message

Dheeraj Jamwal Oct. 21, 2014, 10:49 a.m. UTC

From: Ville Syrjälä <[e-mail]>

When cloning HDMI with other output types, we can't use 12bpc since the
clocks for the other encoder types would be off. So have
intel_hdmi_compute_config() check if there are other encoders besides
HDMI being fed from the same pipe, and if so, pick 8bpc insted if 12bpc.

Signed-off-by: Ville Syrjälä <[e-mail]>
Reviewed-by: Rodrigo Vivi <[e-mail]>
Signed-off-by: Daniel Vetter <[e-mail]>
(cherry picked from commit 718006329556b95c4394cc9163bafac85ccbe2f2)

Signed-off-by: Dheeraj Jamwal <[e-mail]>
---
 drivers/gpu/drm/i915/intel_hdmi.c |   27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

Patch

diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index d13c65d..a89e15a 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -848,6 +848,30 @@  intel_hdmi_mode_valid(struct drm_connector *connector,
 	return MODE_OK;
 }
 
+static bool hdmi_12bpc_possible(struct intel_crtc *crtc)
+{
+	struct drm_device *dev = crtc->base.dev;
+	struct intel_encoder *encoder;
+	int count = 0, count_hdmi = 0;
+
+	if (!HAS_PCH_SPLIT(dev))
+		return false;
+
+	list_for_each_entry(encoder, &dev->mode_config.encoder_list, base.head) {
+		if (encoder->new_crtc != crtc)
+			continue;
+
+		count_hdmi += encoder->type == INTEL_OUTPUT_HDMI;
+		count++;
+	}
+
+	/*
+	 * HDMI 12bpc affects the clocks, so it's only possible
+	 * when not cloning with other encoder types.
+	 */
+	return count_hdmi > 0 && count_hdmi == count;
+}
+
 bool intel_hdmi_compute_config(struct intel_encoder *encoder,
 			       struct intel_crtc_config *pipe_config)
 {
@@ -880,7 +904,8 @@  bool intel_hdmi_compute_config(struct intel_encoder *encoder,
 	 * within limits.
 	 */
 	if (pipe_config->pipe_bpp > 8*3 && intel_hdmi->has_hdmi_sink &&
-	    clock_12bpc <= portclock_limit && HAS_PCH_SPLIT(dev)) {
+	    clock_12bpc <= portclock_limit &&
+	    hdmi_12bpc_possible(encoder->new_crtc)) {
 		DRM_DEBUG_KMS("picking bpc to 12 for HDMI output\n");
 		desired_bpp = 12*3;